Grinding plate-glass.



L. SPAUHTHOLZ & J. WIN'GERSON.

GRINDING PLATE GLASS. APPLICATION FILED DEG.14,1907.

921,477, Patented May 11, 1909.

2 SHEETSSHEET 1.

w m l WITNESEE'. I fgdu gggggzg #W' HH HH gig;

ATTORNEY L. SPAGHTHOLZ & J. WINGERSON.

GRINDING PLATE GLASS. APPLICATION FILED DEG.14,1907.

Patented 11, 1909.

2 S S-SHEET 2.

. ima Lv lar'T 'w;

ORNEY preference, the area face of the large plate.

LUDWIG SPAGHTHOLZ AND JOSEPH WINGERSON, OF KITTANNlNG, PENNSYLVANIA.

enmnme PLATE-GLASS.

Specification of Letters Patent.

Patented May 11, 1909.

Application filed December 14, 1907. semi No. 406,459.

To all whom it may concern:

Be it 'known that we, Lunwre SPAcnTnoLz and JOSEPH Wmennson, residents of Kit tanning, in the county of Armstrong and State of Pennsylvania, ave invented certain new and useful Im rovements in Grinding Plate-Glass, of whic the following is a specification.

This invention provides for grinding plate glass by causing p ates of glass to bear facewise and move one upon the other in such manner that both faces are ground simultaneously.

One feature of the invention is the grinding of several relatively small runner plates while grinding a large plate or field. By

0 each of the runners 1s a fraction of the area of the large platesay approximately one-fourth, so that by applying two of the runner plates at one time to the surface of the large plate, those two runner plates may be ground While grinding the As further characteristic of the improved practice, a certain number of runner plates are rough-ground while rough-grinding the large plate, and then the same runner plates are smooth-ground while similarly grinding the large plate. Thus, if the area ratio is 4 to 1, two of the runner plates are applied to the large plate and by the time they are completely roughround about one-half olthe rocess of roui-grinding the large plate has con accomplished. The two runner plates are then removed and two other unground plates substituted, and the time the substitutedplates have been ull rough-ground, the rough-grinding of the arge late has been comp eted. The smooth-grmding of the plates may then proceed without removing the last applied runner plates until they have been smooth-ground and are ready for the final polishing. When this has been accom lished, the rocess of smooth-grinding the arge lates as proceeded about onehalf towar completion. The runner plates that were first rough-ground are then substituted for the smooth-ground runners, and by the time the smooth-grinding of these substituted plates has been accomplished the smooth-grinding of the large plate has been completed. By thus grindin one plate upon another, practical doub e the area is ground as co ared wit the old practice of grinding a sing e surface b means of iron or other runner or grinding evices. In addi-' tion to increasing the output, the e ense of v maintaining the runner faces is whol y eliminated, and as such runners wear quite rapidly the cost of keep g them in working condition is considerable.

In practicing the invention, it is immaterial whether the runners are positively driven, or propelled solely by their engagement with the large plate ordinarily carried by a rotating table.

Apparatus for practicing the method and also embodyin the improved devices is illustrated in t e accompanying drawings, Figure 1 being a side elevation thereof, partly in section, one of the runners bein shown raised. Fig. 2 is a to plan view of the table and runners, one of the latter showing a clamping mechanism while only the top surface of the other detachable runner head is shown. Fi 3' is a vertical sectional view on a larger sea e of one of the runners. Fi s. 4 and 5 are detail views of the clampin evice. Fig. 6 illustrates a modification o the runner-connecting earing.

Referring to the rawings, 2 desi ates the large rotating table sup orted on t central shaft or axle 3, the ta e and its rotating means being of the usual well known construction.

4' designates a frame above the table, and in'the embodiment here illustrated two vertical runner shafts 5 are journaled therein, each carrying at its lower end the four horizontally radiating arms 6.

7 designates, the runner heads. By preference each head is formed of cast iron, with its upper surface reinforced by circular flange 8 and the four ribs 9 radiating from the cento move on the transverse pin 12 in arm 6. The lower extremities of the yoke-arms are formed" with books 13to engage pins or lugs 14 projectin from opposite sides of rib 9.

The thread stem 15, operating through the upper, endof the v w eel 15', raisesan' tightens the clam with thehooks engaging lugs 14. Two 0 these oke by means of hand clamping devices 0 erate to securely hold the runner head, and t ey are of such construction and may be so manipulated that the runners ma be quickly and conveniently released, 0 accurately center the runners and hold them centered, each shaft 5 may be pro'ected at 16 to enter a corresponding centra depression 16.-in the runner, and a pin or lug 17 may be similarly projected from each of arms 6 to enter a de resslon 17 in each of ribs 9. The runner eads are preferably square. For a table thirty feet in diameter each of the two heads may be 12 feet square. By so operating the runners that the corners of one runner approach the edges of the other runner between its corners, there is no danger of collision, while at the same time their paths of movement so overlap as to efiectua y operate on the whole area of the table. For thus maintaining the runners they may be cared to ether directly by wheels 18,-as in i 2, an thus rotate in the same direction, or y interposing a pinion 19 between gears 18, as in Fig. 6, they may be riven in reverse'directions.

I Inoperation, a plate or field of lass 20 is cemented on table 6 in the usua manner, while a plate 21 is similarly centered to the under face of each of the runners. With two of the runners-in position, the roughgrinding proceeds, sand and water being applied as in' the present practice. As here shown the runners are propelled bytheir contact with the table, but they may be positively driven. N o novelty is claimed in this connection, as in the present" practice the runners are iii some instances driven only by the table and in others are ositivelydriven. As the area of glass on t e table is much larger than the combined areas of the two runners, being double in the example here given, the rough-grinding of the runner plates 21 is comp eted by the time the roughgrinding of the large late 20 is approximately one-half finished At this stage the machme is stopped, and the two runner heads 7 carrying the fully roughround plates are removed and similar hea s with resh plates are substituted for them. The operation then proceeds, and by the time the substituted lates have been rough-ground, the rough-gr nding of large plate 21 has been completed. The plates are then ready for the smooth-grinding process in which a finer abrasive, such as emery, is used. This may proceed at. once, the runner plates last rough- -ound being the first to be smooth-ground, ence those plates are not removed from the machine from the time they are first applied until after the whole rinding operation has been 'comlpleted .and t ey are ready for polishing. y the time these ru'nn'er plates are fully smooth-ground the same process has been approximately oneshalf completed as to the large plate 21, and is fully completed For connecting and disconnecting t e runners, each of shaft 5 may be raised and lowered in frame 4 by a lever 22. It will be noticed in this connection that the runner-com necting gears are of such width that this vertical 'movement of the shaft does not disen-- gage them, and hence the positioning of the runners with relation to each other is always maintained.

.It will be understood that what we term the glass plate or field 21 on table '2 is in practice usually made up of a number of plates of various sha es and areas, the purpose being to cover t e table as fully as possible. 1 The same is true of the smaller. or runner plates. While some plates'may be the exact size of the runners, it more often happens that their surfaces are covered with several lates. Hence, in referrin to the runner p ates and to the large or tab e plate,

We do not necessarily mean a single late but rather a glass covered surface or fie d which may be made up of one plate or several, ac-

cording to circumstances.

The apparatus herein shown and described forms the subject matter of our application Serial No. 417,766, filed February 25, 1908. We claim I y 1. That improvement in the art of grinding late glass by facewise contact of several sma 1 plates with a large plate, consisting in supporting some of the small plates infacewise engagement with the large late, movin the engaging plates relative to each ot er for fully grinding the sma er plates while partially grinding the large plate, substitutmg other smaller plates for those fullyground," and again moving the e a plates relatively to each other for fully grinding the substituted smaller plates and com the grinding of the large plate. hat improvement in the art of grinding plate lass consisting in rotating smaller lates of g ass infacew ise engagement with a arger plate, such smaller lates having a combined area less than t e la'r e late,-

causing the plates tomove with re atlon to each other so as to complete the rep grinding of the smaller, plates whilepartia ly grinding the'large late,-,substitut1ng other small plates for t ose completely rough ground, and simultaneouslly completing the rough-grinding of the su stituted smaller plates and the larger plate.

3. That improvement in the art of grind ing plate lass consisting in .causing small plates of g ass to movably bear facewise andsuccessive'ly on the face of a large plate of glass for completely rou h-grinding a plural-. ity of small plates w 'e snnilarly grmdipfi the large plate, and then causing the sin:

rough-ground plates to bear face-wise and successively on the rough ground large plate,

whereby the several smaller lates are smooth-ground while smooth-grinding the large plate.

4. hat improvement, in the art of grinding plate glass consisting in rotating a large plate of glass, rotatably supporting smaller plates .of glass in facewise engagement with the large plate, completing the rough-grinding of a plurality of small plates by substituting one small plate for another while roughgrmding the large plate, and smooth-grinding the large plate and all of the smaller platesby causlng the several rough-ground small plates to successively .facewise engage the rough-ground large plate, whereby all of the small plates are smooth-ground upon completing the smooth-grinding of the large plate.

5. That improvement in the art of grinding plate glass consisting in rotating a large late, rotatably supporting smaller plates in acewise engagement with the large plate,

completely rough-grinding the small plates when partially rough-grinding the large plate, removing the rough-ground small plates and substituting other small plates, simultaneously completing the rough-grinding of the substituted plates and the large plate, then completely smooth-grinding such substituted plates while partially smoothgrinding the large plate, replacing the completely smooth-ground small plates bythe previously removed rough-ground small plates, and then simultaneously com letin the rough-grinding of the last named smal plates and the large plate.

In testimony whereof we affix our signatures in presence of two witnesses.

LUDWIG, SPACHTHOLZ. J OS. WINGERSON.

Witnesses:

FRANK B. DONALDSON, JAMES MCMASTER. 

